libcamera: controls: Avoid exception in ControlInfoMap count() and find()

The ControlInfoMap count() and find() methods use at() to lookup the
control numerical ID in the idmap_. This causes an exception to be
thrown if the ID doesn't exist in the map. Fix it by using the find()
method instead in find(), and rely on idmap_.count() in count().

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

1 files changed, 16 insertions, 3 deletions

diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
index 93ad2fc6..c23c1b88 100644
--- a/src/libcamera/controls.cpp
+++ b/src/libcamera/controls.cpp
@@ -491,7 +491,12 @@ const ControlInfoMap::mapped_type &ControlInfoMap::at(unsigned int id) const
  */
 ControlInfoMap::size_type ControlInfoMap::count(unsigned int id) const
 {
-	return count(idmap_.at(id));
+	/*
+	 * The ControlInfoMap and its idmap have a 1:1 mapping between their
+	 * entries, we can thus just count the matching entries in idmap to
+	 * avoid an additional lookup.
+	 */
+	return idmap_.count(id);
 }
 
 /**
@@ -502,7 +507,11 @@ ControlInfoMap::size_type ControlInfoMap::count(unsigned int id) const
  */
 ControlInfoMap::iterator ControlInfoMap::find(unsigned int id)
 {
-	return find(idmap_.at(id));
+	auto iter = idmap_.find(id);
+	if (iter == idmap_.end())
+		return end();
+
+	return find(iter->second);
 }
 
 /**
@@ -513,7 +522,11 @@ ControlInfoMap::iterator ControlInfoMap::find(unsigned int id)
  */
 ControlInfoMap::const_iterator ControlInfoMap::find(unsigned int id) const
 {
-	return find(idmap_.at(id));
+	auto iter = idmap_.find(id);
+	if (iter == idmap_.end())
+		return end();
+
+	return find(iter->second);
 }
 
 /**